The world is in balance, more or less, but every so often something goes wrong and human beings in their arrogant self-knowledge know how to fix it.
As Isaac Newton's 3rd Law of Motion states,
For every action there is an equal and opposite reaction
There has to be a relationship between two things for this to happen. Quite often examples of disastrous relationships occur between humans and nature, sometimes with devastating and long term effects.
Wild rabbits are a serious mammalian pest and invasive species in Australia causing millions of dollars of damage to crops. Rabbits in Australia are European rabbits.
They were introduced to Australia in the 18th century with the First Fleet and became widespread after an outbreak caused by an 1859 release. Various methods in the 20th century have been attempted to control the population. Conventional methods include shooting rabbits and destroying their warrens, but these had only limited success. In 1907, a rabbit-proof fence was built in Western Australia in an unsuccessful attempt to contain the rabbits. The myxoma virus, which causes myxomatosis, was introduced into the rabbit population in the 1950s and had the effect of severely reducing the rabbit population.
The rabbits were introduced as a source of food and for hunting.
The Dust Bowl
The Dust Bowl, also known as the Dirty Thirties, was a period of severe dust storms that greatly damaged the ecology and agriculture of the US and Canadian prairies during the 1930s; severe drought and a failure to apply dryland farming methods to prevent wind erosion (the Aeolian processes) caused the phenomenon. The drought came in three waves, 1934, 1936, and 1939–40, but some regions of the high plains experienced drought conditions for as many as eight years. With insufficient understanding of the ecology of the plains, farmers had conducted extensive deep plowing of the virgin topsoil of the Great Plains during the previous decade; this had displaced the native, deep-rooted grasses that normally trapped soil and moisture even during periods of drought and high winds. The rapid mechanization of farm equipment, especially small gasoline tractors, and widespread use of the combine harvester contributed to farmers' decisions to convert arid grassland (much of which received no more than 10 inches (250 mm) of precipitation per year) to cultivated cropland.
In both of the above examples there is an element of self-interest and greed. In the case of the rabbits it was a small group wanting some of the comforts of home, in the second case it was to do with making money more quickly to the detriment of the environment.
Carp were first introduced to Australia in 1859, but numbers exploded in the 1960s after an adapted fish-farming strain was accidently released into the wild.
It's estimated carp make up around 80-90% of the fish biomass within the Murray-Darling Basin, Australia's most important agriculture region.
The carp are prolific breeders that compete with native fish.
Their toothless jaws mean they need to feed at the bottom of rivers, which causes erosion and makes the water turbid, reducing water quality.
Barnaby Joyce, the deputy prime minister, said the only way to get rid of the "bottom-dwelling, mudsucking" fish was to unleash herpes on it.
The A$15m ($11m; £8m) eradication program, dubbed "Carpageddon" by the government, aims to rid the Murray-Darling Basin of carp.
Now there are loads of examples of creatures being introduced for one purpose and having an unfavourable reaction. American Grey squirrels were introduced into the UK to boost the indigenous red squirrel population but instead they have overtaken the smaller locals. There is an inbuilt arrogance in humans that allows us to believe that we know best. We keep getting it wrong!
Ghandi wrote his seven dangers to human virtue which we seem to choose to ignore on too many occasions.